here is a review for the movie:
i’d give it like an 8.5/10, it’s a mess with a bunch of stuff going on but it’s the good kind of mess. feels like it’s kinda on purpose too. i like how it just throws you into the story. it’s not super cohesive like pattinson’s batman, but this one clearly just wants to kick off a whole universe so i don’t really mind, but also wouldn’t call that a plus either.

also the movie wasnt a flop:
https://screenrant.com/james-gunn-superman-profit-dc-studios-report